// PpmEncoder - write out an image as a PPM
//
// Copyright (C)1996,1998 by Jef Poskanzer <jef@acme.com>. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//
// Visit the ACME Labs Java page for up-to-date versions of this and other
// fine Java utilities: http://www.acme.com/java/

package Acme.JPM.Encoders;

import java.io.*;
import java.awt.Image;
import java.awt.image.*;

/**
 * Write out an image as a PPM.
 * <p>Writes an image onto a specified OutputStream in the PPM 
 * file format.</p>
 */
public class PpmEncoder extends ImageEncoder
{

    /**
     * Constructor.
     * @param img The image to encode.
     * @param out The stream to write the PPM to.
     * @throws IOException
     */
    public PpmEncoder( Image img, OutputStream out ) throws IOException
    {
        super( img, out );
    }

    /**
     * Constructor.
     * @param prod The ImageProducer to encode.
     * @param out The stream to write the PPM to.
     * @throws IOException
     */
    public PpmEncoder( ImageProducer prod, OutputStream out ) throws IOException
    {
        super( prod, out );
    }


    void encodeStart( int width, int height ) throws IOException
    {
        writeString( out, "P6\n" );
        writeString( out, width + " " + height + "\n" );
        writeString( out, "255\n" );
    }

    static void writeString( OutputStream out, String str ) throws IOException
    {
        byte[] buf = str.getBytes();
        out.write( buf );
    }

    void encodePixels(
            int x, int y, int w, int h, int[] rgbPixels, int off, int scansize )
    throws IOException
    {
        byte[] ppmPixels = new byte[w * 3];
        for ( int row = 0; row < h; ++row )
        {
            int rowOff = off + row * scansize;
            for ( int col = 0; col < w; ++col )
            {
                int i = rowOff + col;
                int j = col * 3;
                ppmPixels[j    ] = (byte) ( ( rgbPixels[i] & 0xff0000 ) >> 16 );
                ppmPixels[j + 1] = (byte) ( ( rgbPixels[i] & 0x00ff00 ) >> 8 );
                ppmPixels[j + 2] = (byte) (   rgbPixels[i] & 0x0000ff );
            }
            out.write( ppmPixels );
        }
    }

    void encodeDone() throws IOException
    {
        // Nothing.
    }

}
